1. Otorhinolaryngology Department; Hospital Universitario Donostia; San Sebastián Spain
2. Department of Otolaryngology, Instituto de Investigación Biosanitaria ibs.GRANADA; Hospital Universitario Virgen de las Nieves; Granada Spain
3. ENT Department, University Hospital of Salamanca, Ibsal; University of Salamanca; Salamanca Spain
4. Neurotology Unit, Department of Otorhinolaryngology; University Hospital of Badajoz; Badajoz Spain
5. Department of Otorhinolaryngology; Hospital General de Catalunya; Barcelona Spain
6. Department of Otorhinolaryngology; Clínica Universidad de Navarra; Madrid Spain